As a brushless motor, there is a so-called inner rotor type motor having a stator on which a coil is wound and a rotor rotatably provided in a radial inside of the stator. A plurality of permanent magnets are disposed on an outer circumferential surface of the rotor of this type so that magnetic poles thereof are disposed alternately in a circumferential direction. Meanwhile, the stator is configured with a cylindrical stator housing and a cylindrical stator core which is engaged with and fixed to an inner circumferential surface of the stator housing. For example, the stator core is formed in a cylindrical shape by stacking electromagnetic steel plates, and windings are wound around teeth of the stator core.
In this type of brushless motor, to improve magnetic characteristics of the rotor, it is known to change a magnetic orientation of each segment type permanent magnet from a radial orientation (an orientation in a direction in which a magnetic field toward the stator is diffused toward the stator) to a parallel orientation (an orientation in which the magnetic fields toward the stator are parallel to each other toward the stator) or a reverse radial orientation (an orientation in which the magnetic field toward the stator converges toward the stator) (for example, refer to Patent Document 1).